Steam-pressure gage



(No Model.)

J. F. MoBLROY. STEAM PRESSURE GAGE.

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UNITED STATES PATENT ()FFICE.

JAMES F. MCELROY, OF ALBANY, NEW YORK, ASSIGNOR TO THE CONSOLI- DATEDCAR-HEATING COMPANY,

OF WHEELING, WEST VIRGINIA.

STEAM-PRESSURE GAGE.

SPECIFICATION forming part of Letters Patent No. 519,921, dated May 15,1894.

Application filed April 10, 1893 To aZZ whom it may concern.-

Be it known that I, JAMES F. MOELROY, a citizen of the United States,residing at Albany, in the county of Albany and State of New York, haveinvented certain new and useful Improvements in Steam Gages, of whichthe following is a specification, refer- I ence being bad therein to theaccompanying drawings.

The specific object of this invention is to construct a gage which canbe used in connection with steam heating apparatus to indicate therelative amount of heat which is contained in the steam flowing into aregulator or other steam heating appliance. I

obtain this object of my invention by means of a steam gage which,instead of indicating the absolute pressure of steam as the usual steampressure gage is designed to do, indigo cates the momentum of the steam.As the momentum of steam is the direct result of the condensation ofsteam which takes place in the radiator or heating appliance, it isobvione that a gage indicating the momentum of steam must at the sametime be an indicator of the relative amount of condensation which takesplace in the radiator or in other words of the relative amount of heatabsorbed by the radiator or other heating appliance into 0 whlch thesteam flows. The operation of such a gage in connection with a steamheating apparatus would then be to stand at zero when no steam isadmitted into the apparatus, but when steam is admitted it opens 3 5 outand indicates the relative amount of heat contained in the steam whichthe radiator absorbs. With such a gage as an indicator, the valve in thesteam supply pipe can then be intelligently adjusted to the 0 properneeds of the car or room which is to be heated by the radiator. It isquite true that in a certain sense the ordinary steam pressure gage isalso indirectly a steam momentum gage for the reason that the pressure 5of the steam and the momentum of steam are reciprocal factors, that is,the pressure of steam increases or decreases inversely as the momentumdecreases or increases, and thus it might appear that all we have to doto con- 'vert a steam pressure gage into a steam momentum gage would beto reverse the indi- Serial No. 469,747. (No model.)

cation so as to indicate zero at the maximum pressure and from thereopen out as the pressure of steam decreases. This would be all right ifour maximum pressure would be a constant factor, but as there is hardlya heating plant in which the pressure of steam from the boiler does notconstantly vary more or less, or taking as an illustration theconditions found in train heating where we have a train pipe suppliedfrom the locomotive with steam, the pressure of which in the train pipefluctuates and not only this but where each car gets steam at a pressuredifferent from the other cars, it must appear that a steam pressure gageis not a practical device for indicating the momentum of steam. l

My invention has for its object to indicate the momentum irrespective ofthe pressure of the steam on the apparatus and it relates to a gagewhich is therefore not the converse of the steam pressure gage butaccomplishes a new and useful result not accomplished heretofore insteam gages.

I obtain the object of my invention by a steam gage in which the indexis moved bya difierence in pressures produced only when steam is inmotion and to this end I employ two springtubes arranged to move theindex by their differential movement under unequal pressures of steamcausedby a fall in pressure proportionate to the momentum of the psteam, all as more fully hereinafter described in connection with theaccompanying drawings, in which- Figure 1 is a front elevation of mygage with the actuating mechanism exposed and partly in verticalsection. Fig. 2 is asimilar front elevation showing my invention in asimplified form more specifically explained hereinafter. Fig. 3 is adiagram showing the connection of my gage with a steam heatingapparatus. Fig. 4 is a cross-section on line ac-w Fig. 1.

Referring to Figs. 1 and 2, A A are two hollow spring tubes of the usualcharacter employed in steam gages, B is a hollow base to which they areconnected. I

G C are pipes for conveying the steam into and out of the hollow base.

1) is an orifice or a series of orifices between the tube A and pipe 0on one end and the tube A and pipe 0 on the other'end of the hollowbase; all so arranged that if steam flows intothe base through the pipe0 and out through the pipe 0', the tubular spring A is moved by thepressure of the steam before it passes through the orifice and thetubular spring A is moved by the pressure of the steam after it haspassed through the orifice. Attached to the upper end of these springsare connecting links E E which are pivotally attached to opposite endsof the oblique bar F, and so arranged that when equal pressures arecarried on the two springs A and A, the bar F will rock about a fixedpoint inits center. At this point the bar is fulcrumed upon a Wrist Gwhich is carried upon the upper arm of the lever H. This lever II isfulcrumed at I and carries upon its lowerend the rack J which actuatesthe index K through a pinion L.

As far as the operation of the parts so far described is concerned-it isevident that if steam is admitted into the base B no movement could beproduced upon the index as long as the steam is not flowing, but when itflows the orifice produces a resistanceto the free flow of steam andweobtain therefore a difference of pressure of the steam 011 the twosides of the orifice and this difference of pressure will cause thetubes A A to expand differently and the differential movement of thetubes is transmitted to the index and indicatesthe measure of velocityof the steam, as a result of the difference in pressure of the steam inthe tubes. The device therefore as far as described and shown singly inFig. 2, would 7 therefore not be'a true indicator of the momentum as thelatter is the product of velocity and density. For a more perfectworking device I also take into account the factor of the density of thesteam (which depends upon the degree of pressure of the steam). To thisend I arrange the differential motion in such a manner as to giveaproportional increase or decrease to the movement of the index. hand bythe increase or decrease of the pressure of the steam, asshown in Fig. 1in which M M are two bell crank levers. attached to the casing, one armof each is connected to the ends of the springs A A and the other arms Iconnect to the links N N which in turn are pivotally connected to a bar0. This bar at its center is also fulcrumed upon the wrist G and thelatter is now arranged to slide freely upon the arm of the lever H onwhich it-is carried. The result of the last described connection of thetubular springs with the lever H is obviously to lengthen or shorten thearm of the lever H bythe greater or less absolute movement of thesprings under the varying pressure of the steam. It is evident that Imay so arrange and proportion the parts that the point of connection ofthe lever H with the bar F is shifted in such a manner that by theincrease in pressure in A and A, the sliding wrist pin is moved towardthe fulcrum of the lever H, so that a given rise in pressure in the twosprings may be made to have an effect in moving the hand of the gage inproportion thereto.

A gage constructed on the principles herein explained can be madeto'indicate the true momentum of steam in motion and hence the quantityof water which will condense from the steam which passes through it in agiven length of time. It is evident that by taking advantage of theresistance of orifices to the flow of steam, I obtain a difference inpressures as a factor to determine the momentum of the steam in a verysimple and practical manner which greatly simplifies the construction ofsuch a device. The differential movement of the spring tubes alonewouldabsolutely indicate the flow of steam provided the pressures on thetwo sides remained constant, but it will be understood that a fixeddifference of pressure on the two sides will give practically the samevelocity through the orifice regardless of the pressure that may becarried, thus for example a fall from ten to five pounds would givepractically the'same velocity as a fall from thirty to twenty-fivepounds. In the latter instance, however, we would have steam of muchgreater density and hence a greater weight of steam would pass throughin a given-- length of time. Therefore the differ ent movement of thespring tubes determines only the factor of the velocity of the steam and(unless the density of the steam is constant) we will have to increaseor decrease this movement proportionately to the increase or decrease ofthe pressure of the steam (that is its density). To this end I shift thesliding wrist Gupon the lever H proportionately to the absolute movementof the tubular springs under varying pressure of steam and therebyincreaseor decrease the movement of the index hand proportionately tothe increase or decrease of the absolutepressure of the steam actingupon the springs.

In Fig. 3 I show my gage as applied to indicate the momentum of steamflowing from a pipe S (which may be; the train pipe) into a radiator '1through the supply pipes O O. The valveV for controlling theadmission ofsteam may be placed in the-pipe O or O, in either case the gagestands-at zero when this valve is closed, but when the steam isadmitted-into the radiator,- the index will open out and indicateprecisely the relative amount of heat admitted into the radiator.Suppose for instance, the radiator should not condense properly bybecoming filled with water of condensation (a contingency frequentlyencountered in steam heating) the index hand would show it immediatelyto the train hand; now let us compare this action with the action of thesteam pressure gage under like conditions, here evidently the inductionwould show an increase in the pressure on theap- IOC paratus and thetrain hand seeing the pressure rise would reduce the steam and thus dothe opposite from what is required. It is thus evident that as anadjunct to steam heating my device clearly accomplishes a new andimportant result.

While I have heretofore referred to my invention only in connection withsteam, I want it distinctly understood that I claim it broadly forascertaining the momentum of any other gas or fluid, as it is obviousthat its operation is in no wise dependent upon the use of steam.

What I claim as my invention is 1. In a steam or other fluid gage, thecombination with a fluid conductor, of a plurality of movable membersconnected with the conductor and actuated independently by the pressureof the fluid therein, an indicator actuated by the members, and meansfor causing a relative variation in the actuation of the members,substantially as described.

2. In a steam or other fluid gage, the combination with a fluidconductor, of a plurality of hollow springs, communicating with theinterior of the conductor, an index hand, actuating mechanism betweenthe springs and hand, and means at the conductor interposed between thesprings, for causing a differential pressure in the springs,substantially as described.

3. In a steam or other fluid gage, the combination with a fluidconductor, of a plurality of differentially movable tubular springs,communicating with the conductor, indicating mechanism actuated by thesprings and means i or causing the differential movement of the springs,substantially as described.

4;. In a steam or other fluid gage, the combination of a hollow baseprovided with steam inlet and outlet connection, an orifice or series oforifices formed in said base and through which the steam passes, twotubular springs connected to said base and adapted to be actuated by thepressure of the steam on opposite sides of said orifice and indicatingmech anism operated by the difierential movement of said springs,substantially as described.

5. In a steam or other fluid gage, the com-' 6. In a steam or otherfluidgage, the com bination with the tubular springs adapted to bedifferently actuated respectively by different pressures of steam actingupon them, of indicating mechanism comprising an oscillating lever, asliding wrist upon one arm of said lever, intermediate connectionbetween said sliding wrist and the tubular springs for oscillating thelever by the differential movement of the springs, intermediateconnection between said sliding wrist and the springs for controllingthe adjustment of said wrist by the absolute movement of the springs,and an index hand deriving its motion by suitable connection with theother arm of the said lever, substantially as described.

7. In a steam or other fluid gage, the combination with a singleconduit, of a plurality of independent movable members connected withthe conduit and actuated by the pressure of a fluid therein, a partitionin the conduit intermediate the members, having an aperture therein of adiameter less than the diameter of the interior of the conduit, and anindicator actuated by the members, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JAMES F. MGELROY.

\Vitnesses:

EDWIN A. SMITH, WILLIAM P. EDDY.

